Hưng was born in Hóc Môn, in the Mekong Delta of Vietnam, and was raised by his widowed mother, Trương Thị Đức, and his stepfather, Trần Văn Kiển.

He was appointed as Governor and Chief of Phong Dinh sub-region (now Can Tho City) to replace the deceased Colonel Nguyễn Văn Khương, who had fallen in battle.

In the middle of June 1971, he was ordered to hand over the position of the Governor-General of Phong Dinh Sub-division to Colonel Chương Dzềnh Quay (former commander of the 21st Infantry Division).

His forces repelled countless waves of attack by the People's Army of Vietnam (PAVN) infantry, supported by T-54 tanks.

"[2]: 143 However, US advisers reported that Hưng "choked" and "didn't do a damn thing"; and threatened (privately) to shoot his deputy division commander at An Lộc.

[1]: 485  According to Brigadier general John R. McGiffert II, An Lộc would never have held out without the handful of American advisers directing the air strikes and shoring up the local leadership.

When the PAVN made their "Hồ Chí Minh Campaign" final assault on South Vietnam in April 1975, before listening to the capitulation order of President Dương Văn Minh, Hung planned a secret operation to send remaining ARVN soldiers and officers at jungles and military bases that would continue counterattack against VC units after the Fall of Saigon.

He was unable to fight to the death because the townspeople of Cần Thơ had begged him not to resist, believing that it would cause futile bloodshed, and Hưng was one of the five ARVN generals who committed suicide that day.